Heat oven to 220C/fan 200C/gas 7. Place the potatoes in a roasting tin, then rub with 1 tbsp oil and a sprinkling of salt. Roast for 40 mins until the potatoes have turned a deep golden brown. Leave to cool slightly.

Heat a non-stick frying pan. Dry-fry the bacon until crisp.

Meanwhile, make the dressing. Whisk the mustard, vinegar and remaining 1 tbsp oil with a splash of water.

Place potatoes and bacon in a large bowl with the salad leaves, pour over the dressing, then toss well.